The hinged joint is used on pipes, which are in particular intended for transporting fluids at high temperatures, such as e.g. motor vehicle exhaust pipes. These pipes are generally made from metal, so as to be resistant to high temperatures and against the considerable vibrations and oscillations produced by pumps, turbines or engines to which they are connected. For motor vehicle exhaust pipes, it is necessary to provide joints enabling the engine vibrations to be damped in such a way that they are not transferred to the muffler or silencer, which would produce ambient noise. In addition, these joints must provide a good sealing action and must be able to withstand the considerable mechanical stresses and angular deflections produced through vehicle movements, for example, when travelling over a highway speed reduction strip, when cornering or abrupt clutch changing or braking.
It is necessary to connect the exhaust pipes in an articulated or hinged manner, so that the engine can move freely, because it is fitted to mounting supports made from an elastic material.
It is known to connect and join together in hinged manner two exhaust pipe elements, in that their widened ends are so inserted in one another that a spherical joint is formed, or their ends provided with radial flanges are elastically joined with the aid of bolts, which are elastically mounted, a ring gasket ensuring a certain tightness and a sperical joint connection.
However, the use of such joints is limited by their mediocre capacity to damp vibrations or noise, together with their inadequate tightness.
Hose or tubular elements are also used as joints, which have walls in rib form and a limited wall thickness, so that they have a certain elasticity. This permits a flexible hinged connection of the exhaust pipes in various directions, which ensures a complete tightness. This type of joint is used for motor vehicle exhausts. As a result of its great flexibility, the exhaust pipe can absorb difficulty controllable, disordered movements.
However, this tubular construction has a relatively high mechanical fragility with respect to impact from the outside or engine stresses.
As described in French patent 2 531 914, this disadvantage can be obviated by providing at the ends of the pipes to be connected reinforcing flanges and cushions made from slightly compressed metal wire at the contact points between the flanges. This ensures an excellent damping of vibrations and noise. This joint also has an excellent efficiency, but is expensive due to its complexity. Therefore, it is only used in vehicles in the higher price range. Moreover, the arrangements described in the aforementioned patent have a limited rotation range.